Singe

The one damage is a rounding error: it kills almost nothing on its own and rarely trades up. The recoloring is the spell. Turning a creature black until end of turn is a manipulation tool, and which direction it cuts depends on whose creature it is. Hit your own attacker and you can slide it under a color-conditional pump or protection effect, or pull it out of the line of a black-hating answer. Hit a creature already black and you accomplish nothing on the color axis, so the targets that matter are the ones it converts. It also works defensively: a creature made black becomes an invalid target for a spell that cannot target black, so this can shield a permanent from something like Terror rather than expose it. That puts the card in the small family built to rewrite a permanent's color rather than remove it, alongside Sleight of Mind flipping a spell's color and similar one-shot type editors. It is a corner-case enabler wearing a burn spell's clothes, and the corners are narrow enough that it has always lived at the edges: useful to know exists when a deck wants to slip a creature into or out of a color-gated interaction, ignorable when all you want is a point of damage.